Portola Valley Weather
Town • San Francisco Bay Area
Upscale foothill community
Portola Valley weather at a glance
Portola Valley is a town at 459 feet in San Francisco Bay Area. Upscale foothill community. Notable features include sunny, warm, upscale, and rural.
Current conditions are 66°F, feeling like 66°F, with 70% humidity, winds near 3 mph, 100% cloud cover, and a 0% chance of precipitation. Mild and overcast.
The location-specific climate baseline shows an average daily high of 70°F and an average low of 46°F, with about 0.0 hours of sunshine per day and 0.0 hours of morning fog per day. Expected annual precipitation is approximately 27.1 inches.
Current Conditions
Comfort Breakdown
Hourly Forecast
Today
| Time | Temp | Comfort | AQI | Wind | Precip | Conditions |
|---|---|---|---|---|---|---|
| Now | 67° | 81 (B) | — | 3 mph | 0% | ☁️ Cloudy |
| 10pm | 65° | 79 (B) | — | 3 mph | 0% | ☁️ Cloudy |
| 11pm | 62° | 75 (B) | — | 4 mph | 0% | ☁️ Cloudy |
Tomorrow
| Time | Temp | Comfort | AQI | Wind | Precip | Conditions |
|---|---|---|---|---|---|---|
| 12am | 59° | 70 (B-) | — | 4 mph | 0% | ☁️ Cloudy |
| 1am | 57° | 62 (C) | — | 3 mph | 0% | ☁️ Cloudy |
| 2am | 56° | 61 (C) | — | 1 mph | 0% | ☁️ Cloudy |
| 3am | 56° | 61 (C) | — | 1 mph | 0% | ☁️ Cloudy |
| 4am | 55° | 59 (C-) | — | 2 mph | 0% | ☁️ Cloudy |
| 5am | 56° | 61 (C) | — | 3 mph | 0% | ☁️ Cloudy |
| 6am | 56° | 61 (C) | — | 2 mph | 0% | ☁️ Cloudy |
| 7am | 56° | 61 (C) | — | 2 mph | 0% | ☁️ Cloudy |
| 8am | 58° | 69 (C) | — | 4 mph | 0% | ☁️ Cloudy |
How to read the Portola Valley hourly chart
The hourly chart follows the next 48 forecast hours at Portola Valley. Use the temperature view to see warming and cooling through the day, and the comfort view to see when the combined temperature, wind, clouds, precipitation, and air quality should feel most favorable.
The wind view compares sustained wind with stronger gusts at Portola Valley. The AQI view uses the current observation for “Now” and modeled AQI-equivalent guidance for later hours when forecast smoke data is available.
Weather Maps
GOES-West Infrared
Precipitation
View marine layer conditions in 3D
Coming soon
About the weather maps for Portola Valley
Each preview is centered on Portola Valley, with the red pin marking its approximate location. Satellite imagery provides cloud context, radar shows nearby precipitation, and the fog view shows the marine-layer or low-cloud field when that regional layer is available.
These images cover a wider area than the point forecast, so a nearby cloud or rain band may not be directly over Portola Valley. Open a preview for the interactive map and its latest timestamp before making a weather-sensitive decision.
7-Day Forecast
| Day | High/Low | Comfort | Precip | Conditions |
|---|---|---|---|---|
| Today | 82° / 57° | 81 (B) | 0% | ☀️ Sunny |
| Mon🏆 Best | 81° / 55° | 83 (B) | 0% | ☀️ Sunny |
| Tue | 82° / 52° | 81 (B) | 0% | ☀️ Sunny |
| Wed | 88° / 52° | 69 (C) | 0% | ☀️ Sunny |
| Thu | 85° / 53° | 77 (B) | 0% | ☀️ Sunny |
| Fri | 84° / 53° | 76 (B) | 0% | ☀️ Sunny |
| Sat | 84° / 53° | 76 (B) | 1% | ☀️ Sunny |
Best day this week: Mon (Comfort score: 83)
Nearby Temperature Comparison
Conditions at nearby San Francisco Bay Area destinations
Tip: Bay Area temps can vary 20-30°F within a short distance due to microclimates.
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Portola Valley climate comparisons mean
These cards compare recent conditions at Portola Valley with the available local baseline. Temperature and year-to-date rainfall use long-term normals when available; fog, sunshine, wind, and comfort use the matching recent or modeled baseline identified on each card.
Positive and negative differences describe how Portola Valley departs from its own usual pattern. They should not be read as a direct comparison with another city or as a forecast beyond the period shown.
Historical Climate Data
Long-term weather patterns and climate data
Data sources: NOAA URMA for recent temperature history, NOAA Stage IV for recent precipitation, NOAA HRRR for fog, cloud, wind, humidity, and sunshine signals, and NOAA 1991-2020 climate normals for long-term baselines.
Climate Overview
Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline
🌟 Best Months to Visit
⚠️ Challenging Months
Monthly Breakdown
| Month | Comfort | High/Low | ☀️ Sun | 🌫️ Fog | 💧 Rain | Perfect |
|---|---|---|---|---|---|---|
| August 2024 | 93 | 81° / 56.5° | 12.2h | 3d | 0.08" | 27 |
| September 2024 | 93 | 81.1° / 56.8° | 10.9h | 4d | 0.11" | 28 |
| October 2024 | 91 | 78.8° / 57.1° | 9.9h | 1d | 0.2" | 28 |
| November 2024 | 81 | 61.2° / 46.5° | 7.1h | 6d | 2.32" | 22 |
| December 2024 | 75 | 59.3° / 45.5° | 6.4h | 9d | 4.58" | 17 |
| January 2025 | 84 | 57.1° / 41.7° | 7.8h | 7d | 0.58" | 25 |
| February 2025 | 75 | 59.1° / 44.4° | 6.7h | 7d | 4.98" | 16 |
| March 2025 | 78 | 59.7° / 44.7° | 9.2h | 5d | 3.35" | 17 |
| April 2025 | 90 | 67.2° / 46.6° | 10.7h | 7d | 0.8" | 24 |
| May 2025 | 91 | 73° / 49.8° | 12.7h | 6d | 0.13" | 29 |
| June 2025 | 95 | 76° / 52.1° | 13.5h | 0d | 0" | 30 |
| July 2025 | 94 | 76° / 55.2° | 12.9h | 5d | 0" | 30 |
| August 2025 | 93 | 80.6° / 57.1° | 12.1h | 2d | 0.04" | 30 |
| September 2025 | 90 | 79.6° / 59.8° | 10.3h | 4d | 0.36" | 25 |
| October 2025 | 89 | 70.5° / 53.4° | 8.7h | 6d | 1.27" | 25 |
| November 2025 | 78 | 62.9° / 50° | 7.1h | 9d | 4.72" | 16 |
| December 2025 | 72 | 56.9° / 45.5° | 6.3h | 11d | 4.39" | 12 |
| January 2026 | 79 | 58.1° / 44.4° | 7.2h | 4d | 3.3" | 21 |
| February 2026 | 78 | 61.1° / 46.6° | 7.5h | 4d | 5.72" | 18 |
| March 2026 | 93 | 74.2° / 51.9° | 10.6h | 2d | 0.84" | 29 |
| April 2026 | 86 | 66.2° / 48.9° | 10.8h | 5d | 3.84" | 23 |
| May 2026 | 85 | 66.8° / 50.7° | 10.2h | 6d | 0.15" | 8 |
Climate Trends
Average Temperature by Month
About the Portola Valley climate charts
The temperature chart compares average monthly highs and lows at Portola Valley, showing both the seasonal cycle and the typical day-to-night range. The comfort chart summarizes how often the combined weather pattern is favorable rather than judging temperature alone.
Precipitation shows the total recorded or modeled rainfall for each month at Portola Valley. Sunshine compares average bright-sky hours with the daylight available, while fog shows the average number of morning fog or low-cloud hours per day. Switch between the chart tabs to compare the same months across each measure.
Hourly Temperature, Fog, Wind, Cloud Cover, and Solar Radiation Patterns
Average local hour by month from 2014-09-30 to 2026-04-30
How to read the temperature heatmap for Portola Valley
This heatmap shows how average temperature at Portola Valley changes by hour and month. Read left to right for the seasons and top to bottom for the time of day; warmer colors identify the usual afternoon peaks and cooler colors show overnight and winter lows.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.
How to read the fog heatmap for Portola Valley
This heatmap shows when fog or low cloud is most likely at Portola Valley. Darker cells mark month-and-hour combinations with a stronger historical fog signal, which helps separate overnight or morning fog from cloud that tends to linger into the afternoon.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.
How to read the wind heatmap for Portola Valley
This heatmap shows the typical hourly wind pattern at Portola Valley through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.
How to read the cloud cover heatmap for Portola Valley
This heatmap shows average cloud cover at Portola Valley for every month and hour. Use it to see whether cloudiness is mainly an overnight and morning pattern or commonly persists during the part of the day you plan to visit.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.
How to read the solar radiation heatmap for Portola Valley
This heatmap shows the average solar radiation reaching Portola Valley by month and hour. Brighter cells indicate the strongest typical sun, while muted cells can reflect nighttime, shorter winter days, cloud cover, smoke, or terrain shading.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.
Location Details
Frequently Asked Questions
Everything you need to know about weather and visiting Portola Valley
What is the weather at Portola Valley right now?
Current conditions at Portola Valley are 66°F, feeling like 66°F, with 70% humidity, winds near 3 mph, 100% cloud cover, and a 0% chance of precipitation. Mild and overcast
What temperatures are typical at Portola Valley?
The location-specific record for 1991-01-01 through 2020-12-31 shows an average daily high of 70°F and an average low of 46°F at Portola Valley. These are averages across the year; the monthly climate table on this page shows the warmer and cooler seasons separately.
How much rain does Portola Valley get?
The location-specific climate baseline estimates about 27.1 inches of precipitation and 87 days with measurable rain in a typical year at Portola Valley. The monthly breakdown shows when that rain is most likely.
How often is Portola Valley foggy?
Portola Valley averages about 0.0 hours of morning fog per day across the location-specific climate baseline, with approximately 0 foggy days in a typical year. Fog varies considerably by season, so check the monthly breakdown and current forecast for visit planning.
What are the best months to visit Portola Valley for comfortable weather?
Based on the destination's recorded comfort, temperature, sunshine, rain, and fog data, the strongest months are June 2025 (76°F/52°F average high/low and a 95 comfort score), July 2025 (76°F/55°F average high/low and a 94 comfort score), and August 2024 (81°F/57°F average high/low and a 93 comfort score). “Best” depends on the activity, so use the monthly table for the exact tradeoffs.
What kind of destination is Portola Valley?
Portola Valley is a town at 459 feet. Upscale foothill community. Notable features include sunny, warm, upscale, and rural.